1. Technical Field
This invention relates generally to surgical navigation systems. More particularly, this invention relates to a substrate removably attached to a user that assists the user in determining the position of a point on an anatomical structure within a patient.
2. Background Art
The use of surgical navigation systems for assisting surgeons during surgery is quite common. Some systems are used to determine points of interest on organs or bony structures. Determining the precise location of a point on these anatomical structures has proved difficult. One typical surgical technique is to use rigid pointer devices, such as the one described in U.S. Pat. No. 5,617,857, with surgical navigation trackers attached thereto. These conventional systems, however, have numerous problems. Present systems suffer from pointer lift-off concerns, where the tip of the pointer that should correspond to the point desired to be located on the anatomical structure has moved away from the bony structure or organ when the location is determined. Other problems arise with conventional techniques when the anatomical structure is relatively inaccessible, especially to rigid pointers that cannot bend around obstructions within the patient to reach the anatomical structure. This is especially problematic with the increased use of smaller incisions for surgical procedures. Also of great importance is the wasted time surgeons must tolerate when switching from pointers to the other surgical tools needed to operate on the patient. The present invention provides a system for determining the global position of a point on an anatomical structure that does not suffer from the same lift-off, inaccessibility, or time wasting problems of conventional techniques.